Replaces percentual values with pixel values for the tts:extent attribute of the TT node.
NOTE: This function fixes an errorous TTML document, as the extent value of the TT node
, according to TTML standard, does not support percentual values:
https://www.w3.org/TR/2018/REC-ttml2-20181108/#style-attribute-extent
Replaces percentual values with pixel values for the tts:extent attribute of the TT node. NOTE: This function fixes an errorous TTML document, as the extent value of the TT node , according to TTML standard, does not support percentual values: https://www.w3.org/TR/2018/REC-ttml2-20181108/#style-attribute-extent